Why are all pure orange cats males and calicos female?

Answer 1

Hi there...not all orange tabbies are male and there are some male calicos, however they are sterile.

For a cat to be calico, it must simultaneously express both of the alleles, O (orange) and o (black), which are two versions of the same gene, located at the same location on the X chromosome. Males normally cannot do this: they can have only one allele, as they have only one X chromosome. Over 90% of tortoiseshell cats are females. Occasionally a male calico is born. These may have Klinefelter's syndrome, carrying an extra X chromosome, and will almost always be sterile or they may be a chimera resulting from the fusion of two differently coloured embryos.

The sex-linked orange gene, O, determines if there will be orange fur. This gene only appears on the X chromosome. In cats with orange fur, phaeomelanin (orange pigment) completely replaces eumelanin (black pigment).

For males, O results in orange fur, and o means that the O gene will determine the color (the black or brown color may be broken up into patterns if the cat has the agouti gene), so this would be epistatic to agouti locus.

For females, OO results in orange fur, oo means that the gene will determine the color (patterns if the cat has the agouti gene), and Oo results in a tortoiseshell cat, in which the B gene determines the color of the dark patches. A cat with Oo and white spotting genes will be a calico. The reason for the patchwork effect in female cats heterozygous for the O gene (Oo) is "X chromosome inactivation" - one or the other X chromosome in every cell in the embryo is randomly inactivated, and the gene in the other X chromosome is expressed (see barr body).

Rufous polygenes, as yet unidentified, that affect the richness of the orange gene's expression.

Answer 2

I read that there are some male calicos. It is rare but there are some. As for pure orange cats I didn't know all of them were female. I have had several male cats that color. I know of at least 2 that were males that we have had. It's in their genes as to why most of them are male and females. It's kind of like in humans where the gene for baldness is mostly passed on to the males.

Answer 3

we have had our cat for over ten years now. she is orange and longhaired. i never heard the orange thing but have heard that all calicos are female. the calicos ive come across have been female. guess it is in the genes.

Answer 4

I have two female longhaired ginger cats not all of them are male they do have a brother froma different litter though have not heard about the calico thing though

Answer 5

i wasnt aware of this...i mean about the orange cats being male i was aware that calicos are female 99% of the time...

Answer 6

They're not.
Calico's are 99% female, but there are some males.
Orange cats are about 60/40 male to female,

Answer 7

orange coloration in cats is dictated by an autosomal recessive allele on the X chromosome. A male only needs one copy of the gene to express the orange phenotype while females need both X chromosomes to have the allele to express the orange phenotype. So yes! it is rare from a genetic standpoint.

Answer 8

all calicos are most likeley females cause male calicos are rare and its hard to find one and they are worth alot of money and orange cats i had alot of female orange kittens. i dont think its hard to come buy.

Answer 9

not all orange cats are male.. and there are some male calicos

Answer 10

Because the gene for those particular colours are on the gender-specific chromosomes.